Question

A tire company wants to know how long a tire lasts on average. Suppose they know...

A tire company wants to know how long a tire lasts on average. Suppose they know that the population variance for tire life is 1,000,000.  A sample of 400 tires yields the average life of tire as 27,000 miles.

            Construct and interpret a 98% confidence interval for population mean.   

Homework Answers

Answer #1

Z for 98% confidence interval = Z0.01 = 2.33

confidence interval

                              

                              

                               = (26883.5 , 27116.5)

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